I am using a Range chart to create a Gannt Chart of sorts. I am attempting to do two things:
1) Change the background colour of the range chart based upon one of two Category groups, I have two groups, an outer and an inner, and I would like the background colour to change based on the outer grouping. I have a piece of code that determines a colour but, i'm having trouble applying that to the background. I was hoping interlacing colour would help me, that you aren't able to determine the frequency of the interlacing from what I can tell.
The code I'm using is:
Private colorPalette As String() = { "#C85200", "#FF800E", "#5F9ED1",
"#2CA02C", "#A59D93", "#B8341B", "#352F26", "#F1E7D6", "#E16C56", "#CFBA9B"}
Private count As Integer = 0
Private mapping As New System.Collections.Hashtable()
Public Function GetColor(ByVal groupingValue As String) As String
If mapping.ContainsKey(groupingValue) Then
Return mapping(groupingValue)
End If
Dim c As String = colorPalette(count Mod colorPalette.Length)
count = count + 1
mapping.Add(groupingValue, c)
Return c
End Function
2) Position the X and Y axis labels between the major grid lines. The X axis is a date, and the end user would like the date to be between the two grid lines (representing a day) rather than on each grid line, I've had a look around but can't seem to find anything relevant.
Any help or guidance would be appreciated, thanks!
Related
I want to show the most recent 10 bins for box plot.
If a filter is applied to the bar chart or line chart, the box plot should show the most recent 10 records according to those filters.
I made dimension by date(ordinal). But I am unable to get the result.
I didn’t get how to do it with a fake group. I am new to dc.js.
The pic of scenario is attached. Let me know if anyone need more detail to help me.
in image i tried some solution by time scale.
You can do this with two fake groups, one to remove the empty box plots, and one to take the last N elements of the resulting data.
Removing empty box plots:
function remove_empty_array_bins(group) {
return {
all: function() {
return group.all().filter(d => d.value.length);
}
};
}
This just filters the bins, removing any where the .value array is of length 0.
Taking the last N elements:
function cap_group(group, N) {
return {
all: function() {
var all = group.all();
return all.slice(all.length - N);
}
};
}
This is essentially what the cap mixin does, except without creating a bin for "others" (which is somewhat tricky).
We fetch the data from the original group, see how long it is, and then slice that array from all.length - N to the end.
Chain these fake together when passing them to the chart:
chart
.group(cap_group(remove_empty_array_bins(closeGroup), 5))
I'm using 5 instead of 10 because I have a smaller data set to work with.
Demo fiddle.
This example uses a "real" time scale rather than ordinal dates. There are a few ways to do ordinal dates, but if your group is still sorted from low to high dates, this should still work.
If not, you'll have to edit your question to include an example of the code you are using to generate the ordinal date group.
I am using working on Tableau stacked bar chart.
The bar chart represents the total %. Therefore, the length of bar chart is equal.
Now I would like to sort the dimension (referee) based on the values of legends ( highest to lowest).
can anyone suggest me how to do it.
I also attached the packaged workfile here
Here is the picture of sort screen;
Level of data source below:
Below is the screen shot based on the final answer provided:
Thanks,
Zep
So to get this you first need to get a calc field that gets the win %:
SUM(IF [FTR] = 'AWins' OR [FTR] = 'Hwins' THEN 1 END)/COUNTD([Game ID])
This can then be used to rank the referees:
Now the reason that it may not be working for you with your technique is that you're sorting on COUNTD(Wins) which is the total number of wins, not the percentage wins for the ref. So someone that has just played more games may come up higher in the rank
Now you have the calc field, you can go back to your report and sort on the new field:
I rearranged the legend so you can see that the ref with the best % wins are shown first (red and blue bars)
If you don't want it sorted by win %, then change the calc field to:
SUM(IF [FTR] = 'AWins' OR [FTR] = 'Hwins' THEN 1 END)
For the COUNTD of games, if you only have the date and the game available and want to create an ID from that that is unique, create a calc field like this:
game-date-id = STR([game]) + STR(' ') + STR(date)
This will then be used in your COUNTD if statement:
SUM(IF [FTR] = 'AWins' OR [FTR] = 'Hwins' THEN 1 END)/COUNTD([game-date-id])
I have attached the picture of the dashboard.
I want to sort the referee based of Hwin
Yeah. It did not work out as expected
Good Evening Everyone,
I'm trying to take the data from a database full of hour reports (name, timestamp, hours worked, etc.) and create a plot using dc.js to visualize the data. I would like the timestamp to be on the x-axis, the sum of hours for the particular timestamp on the y-axis, and a new bar graph for each unique name all on the same chart.
It appears based on my objectives that using crossfilter.js the timestamp should be my 'dimension' and then the sum of hours should be my 'group'.
Question 1, how would I then use the dimension and group to further split the data based on the person's name and then create a bar graph to add to my composite graph? I would like for the crossfilter.js functionality to remain intact so that if I add a date range tool or some other user controllable filter, everything updates accordingly.
Question 2, my timestamps are in MySQL datetime format: YYYY-mm-dd HH:MM:SS so how would I go about dropping precision? For instance, if I want to combine all entries from the same day into one entry (day precision) or combine all entries in one month into a single entry (month precision).
Thanks in advance!
---- Added on 2017/01/28 16:06
To further clarify, I'm referencing the Crossfilter & DC APIs alongside the DC NASDAQ and Composite examples. The Composite example has shown me how to place multiple line/bar charts on a single graph. On the composite chart I've created, each of the bar charts I've added a dimension based off of the timestamps in the data-set. Now I'm trying to figure out how to define the groups for each. I want each bar chart to represent the total time worked per timestamp.
For example, I have five people in my database, so I want there to be five bar charts within the single composite chart. Today all five submitted reports saying they worked 8 hours, so now all five bar charts should show a mark at 01/28/2017 on the x-axis and 8 hours on the y-axis.
var parseDate = d3.time.format('%Y-%m-%d %H:%M:%S').parse;
data.forEach(function(d) {
d.timestamp = parseDate(d.timestamp);
});
var ndx = crossfilter(data);
var writtenDimension = ndx.dimension(function(d) {
return d.timestamp;
});
var hoursSumGroup = writtenDimension.group().reduceSum(function(d) {
return d.time_total;
});
var minDate = parseDate('2017-01-01 00:00:00');
var maxDate = parseDate('2017-01-31 23:59:59');
var mybarChart = dc.compositeChart("#my_chart");
mybarChart
.width(window.innerWidth)
.height(480)
.x(d3.time.scale().domain([minDate,maxDate]))
.brushOn(false)
.clipPadding(10)
.yAxisLabel("This is the Y Axis!")
.compose([
dc.barChart(mybarChart)
.dimension(writtenDimension)
.colors('red')
.group(hoursSumGroup, "Top Line")
]);
So based on what I have right now and the example I've provided, in the compose section I should have 5 charts because there are 5 people (obviously this needs to be dynamic in the end) and each of those charts should only show the timestamp: total_time data for that person.
At this point I don't know how to further breakup the group hoursSumGroup based on each person and this is where my Question #1 comes in and I need help figuring out.
Question #2 above is that I want to make sure that the code is both dynamic (more people can be handled without code change), when minDate and maxDate are later tied to user input fields, the charts update automatically (I assume through adjusting the dimension variable in some way), and if I add a names filter that if I unselect names that the chart will update by removing the data for that person.
A Question #3 that I'm now realizing I'll want to figure out is how to get the person's name to show up in the pointer tooltip (the title) along with timestamp and total_time values.
There are a number of ways to go about this, but I think the easiest thing to do is to create a custom reduction which reduces each person into a sub-bin.
First off, addressing question #2, you'll want to set up your dimension based on the time interval you're interested in. For instance, if you're looking at days:
var writtenDimension = ndx.dimension(function(d) {
return d3.time.hour(d.timestamp);
});
chart.xUnits(d3.time.hours);
This will cause each timestamp to be rounded down to the nearest hour, and tell the chart to calculate the bar width accordingly.
Next, here's a custom reduction (from the FAQ) which will create an object for each reduced value, with values for each person's name:
var hoursSumGroup = writtenDimension.group().reduce(
function(p, v) { // add
p[v.name] = (p[v.name] || 0) + d.time_total;
return p;
},
function(p, v) { // remove
p[v.name] -= d.time_total;
return p;
},
function() { // init
return {};
});
I did not go with the series example I mentioned in the comments, because I think composite keys can be difficult to deal with. That's another option, and I'll expand my answer if that's necessary.
Next, we can feed the composite line charts with value accessors that can fetch the value by name.
Assume we have an array names.
compositeChart.shareTitle(false);
compositeChart.compose(
names.map(function(name) {
return dc.lineChart(compositeChart)
.dimension(writtenDimension)
.colors('red')
.group(hoursSumGroup)
.valueAccessor(function(kv) {
return kv.value[name];
})
.title(function(kv) {
return name + ' ' + kv.key + ': ' + kv.value;
});
}));
Again, it wouldn't make sense to use bar charts here, because they would obscure each other.
If you filter a name elsewhere, it will cause the line for the name to drop to zero. Having the line disappear entirely would probably not be so simple.
The above shareTitle(false) ensures that the child charts will draw their own titles; the title functions just add the current name to those titles (which would usually just be key:value).
So this is a question regarding a rather specific problem. As I know from Gordon, main contributor of dc.js, there is no support for elasticY(true) function for logarithmic scales.
So, after knowing this, I tried to implement my own solution, by building a workaround, inside dc.js's renderlet event. This event is always triggered by a click of the user onto the barchart. What I wanted to do is this:
let groupSize = this.getGroupSize(fakeGroup, this.yValue);
let maximum = group.top(1)[0].value;
let minimum = group.top(groupSize)[groupSize-1].value;
console.log(minimum, maximum);
chart.y(d3.scale.log().domain([minimum, maximum])
.range(this.height, 0)
.nice()
.clamp(true));
I thought, that at this point the "fakeGroup" (which is just group.top(50)) contains only the data points that are NOT filtered out after the user clicked somewhere. However, this group always contains all data points that are in the top 50 and doesn't change on filter events.
What I really wanted is get all data points that are NOT filtered out, to get a new maximum and minimum for the yScale and rescale the yAxis accordingly by calling chart.y(...) again.
Is there any way to get only data rows that are still in the chart and not filtered out. I also tried using remove_empty_bins(group) but didn't have any luck with that. Somewhere is always all() or top() missing, even after giving remove_empty_bins both functions.
This is how i solved it:
I made a function called rescale(), which looks like this:
rescale(chart, group, fakeGroup) {
let groupSize = this.getGroupSize(fakeGroup, this.yValue);
let minTop = group.top(groupSize)[groupSize-1].value;
let minimum = minTop > 0 ? minTop : 0.0001;
let maximum = group.top(1)[0].value;
chart.y(d3.scale.log().domain([minimum, maximum])
.range(this.height, 0)
.nice()
.clamp(true));}
I think the parameters are pretty self-explanatory, I just get my chart, the whole group as set by dimension.group.reduceSum and a fake group I created, which contains the top 50 elements, to reduce bar count of my chart.
The rescale() method is called in the event listener
chart.on('preRedraw', (chart) => {
this.rescale(chart, group, fakeGroup);
}
So what I do is re-defining (re-setting min and max values regarding filtered data) the charts yAxis everytime the chart gets redrawn, which happens to also be every time one of my charts is filtered. So now, the scale always fits the filtered data the chart contains after filtering another chart.
I have a list of values each with latitude and longitude. I'm looking to create a translucent heatmap image to overlay on Google Maps. I know there are server side and flash based solutions already, but I want to build this in javascript using the canvas tag.
However, I can't seem to find a concise description of the algorithm used to turn coordinates and values into a heatmap. Can anyone provide or link to one?
Thanks.
The basic idea would be to create a grid and project every lat,lng coord to that grid. I would use a 2D array of ints.
The psuedo-code would be:
for each coord
cell = coord projected to grid
increment cell value
end
for 0 to # of passes
for each row
for each col
if grid[row,col] > 0 then
grid[row,col] += 1
increment_adjacent_cells(row, col)
end
end
end
end
So, the idea is that the higher the int value, the hotter that cell is. increment_adjacent_cells should increment the values in all 8 adjacent cells.
I have tried to solve this in javascript using the canvas element, here is my current result:
http://gist.github.com/346165
I have to fix the gaussian filter and the color mapping, because it doesn't give good results currently.
A faster way of building a heatmap could be to use a queue:
Pseudocode:
Add an element to queue (first in heatmap(x,y, val))
While (!queue.isEmpty())
{
elem = queue.pop()
queue.push(elem.x + 1, elem.y, val-1)
queue.push(elem.x - 1, elem.y, val-1)
queue.push(elem.x, elem.y + 1, val-1)
queue.push(elem.x, elem.y - 1, val-1)
}
This saves on tons of iterations!
Look at this project if you are looking for something that looks more like 'tv weather maps':
https://github.com/optimisme/javascript-temperatureMap